# Setting up ExternalDNS for Services on DigitalOcean This tutorial describes how to setup ExternalDNS for usage within a Kubernetes cluster using DigitalOcean DNS. Make sure to use **>=0.4.2** version of ExternalDNS for this tutorial. ## Creating a DigitalOcean DNS zone If you want to learn about how to use DigitalOcean's DNS service read the following tutorial series: [An Introduction to Managing DNS](https://www.digitalocean.com/community/tutorial_series/an-introduction-to-managing-dns), and specifically [How To Set Up a Host Name with DigitalOcean DNS](https://www.digitalocean.com/community/tutorials/how-to-set-up-a-host-name-with-digitalocean) Create a new DNS zone where you want to create your records in. Let's use `example.com` as an example here. ## Creating DigitalOcean Credentials Generate a new personal token by going to [the API settings](https://cloud.digitalocean.com/settings/api/tokens) or follow [How To Use the DigitalOcean API v2](https://www.digitalocean.com/community/tutorials/how-to-use-the-digitalocean-api-v2) if you need more information. Give the token a name and choose read and write access. The token needs to be passed to ExternalDNS so make a note of it for later use. The environment variable `DO_TOKEN` will be needed to run ExternalDNS with DigitalOcean. ## Deploy ExternalDNS Connect your `kubectl` client to the cluster you want to test ExternalDNS with. Then apply one of the following manifests file to deploy ExternalDNS. ### Manifest (for clusters without RBAC enabled) ```yaml apiVersion: apps/v1 kind: Deployment metadata: name: external-dns spec: strategy: type: Recreate selector: matchLabels: app: external-dns template: metadata: labels: app: external-dns spec: containers: - name: external-dns image: registry.opensource.zalan.do/teapot/external-dns:latest args: - --source=service # ingress is also possible - --domain-filter=example.com # (optional) limit to only example.com domains; change to match the zone created above. - --provider=digitalocean env: - name: DO_TOKEN value: "YOUR_DIGITALOCEAN_API_KEY" ``` ### Manifest (for clusters with RBAC enabled) ```yaml apiVersion: v1 kind: ServiceAccount metadata: name: external-dns --- apiVersion: rbac.authorization.k8s.io/v1beta1 kind: ClusterRole metadata: name: external-dns rules: - apiGroups: [""] resources: ["services"] verbs: ["get","watch","list"] - apiGroups: [""] resources: ["pods"] verbs: ["get","watch","list"] - apiGroups: ["extensions"] resources: ["ingresses"] verbs: ["get","watch","list"] - apiGroups: [""] resources: ["nodes"] verbs: ["list"] --- apiVersion: rbac.authorization.k8s.io/v1beta1 kind: ClusterRoleBinding metadata: name: external-dns-viewer roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: external-dns subjects: - kind: ServiceAccount name: external-dns namespace: default --- apiVersion: apps/v1 kind: Deployment metadata: name: external-dns spec: strategy: type: Recreate selector: matchLabels: app: external-dns template: metadata: labels: app: external-dns spec: serviceAccountName: external-dns containers: - name: external-dns image: registry.opensource.zalan.do/teapot/external-dns:latest args: - --source=service # ingress is also possible - --domain-filter=example.com # (optional) limit to only example.com domains; change to match the zone created above. - --provider=digitalocean env: - name: DO_TOKEN value: "YOUR_DIGITALOCEAN_API_KEY" ``` ## Deploying an Nginx Service Create a service file called 'nginx.yaml' with the following contents: ```yaml apiVersion: apps/v1 kind: Deployment metadata: name: nginx spec: selector: matchLabels: app: nginx template: metadata: labels: app: nginx spec: containers: - image: nginx name: nginx ports: - containerPort: 80 --- apiVersion: v1 kind: Service metadata: name: nginx annotations: external-dns.alpha.kubernetes.io/hostname: my-app.example.com spec: selector: app: nginx type: LoadBalancer ports: - protocol: TCP port: 80 targetPort: 80 ``` Note the annotation on the service; use the same hostname as the DigitalOcean DNS zone created above. ExternalDNS uses this annotation to determine what services should be registered with DNS. Removing the annotation will cause ExternalDNS to remove the corresponding DNS records. Create the deployment and service: ```console $ kubectl create -f nginx.yaml ``` Depending where you run your service it can take a little while for your cloud provider to create an external IP for the service. Once the service has an external IP assigned, ExternalDNS will notice the new service IP address and synchronize the DigitalOcean DNS records. ## Verifying DigitalOcean DNS records Check your [DigitalOcean UI](https://cloud.digitalocean.com/networking/domains) to view the records for your DigitalOcean DNS zone. Click on the zone for the one created above if a different domain was used. This should show the external IP address of the service as the A record for your domain. ## Cleanup Now that we have verified that ExternalDNS will automatically manage DigitalOcean DNS records, we can delete the tutorial's example: ``` $ kubectl delete service -f nginx.yaml $ kubectl delete service -f externaldns.yaml ```